U. Hanson et B. Persson, EPIDEMIOLOGY OF PREGNANCY-INDUCED HYPERTENSION AND PREECLAMPSIA IN TYPE-1 (INSULIN-DEPENDENT) DIABETIC PREGNANCIES IN SWEDEN, Acta obstetricia et gynecologica Scandinavica, 77(6), 1998, pp. 620-624
Background. The object of this study was to examine if there is an ass
ociation between pregnancy-induced hypertension (PIH) and/or preeclamp
sia (PE) and glycemic control assessed by HbA1c in early type 1 diabet
ic pregnancy, as well as factors such as maternal age, parity, duratio
n of diabetes, presence of diabetes microangiopathy. Methods. The nati
onwide collaborative study included 491 type 1 diabetic pregnancies co
rresponding to about 80% of the diabetic pregnancies during the study
period 1983-1985. A blood sample for determination of HbA1c was obtain
ed in early gestation (median 9 (5-16) weeks). Results. The rate of PI
H/PE was 20.6% in the type 1 diabetic pregnancies compared to 5.0% in
the background population. The type 1 diabetic pregnancies complicated
by PIH/PE were associated with significantly longer duration of diabe
tes, higher initial HbA1c (8.1% vs 7.4%, p<0.01), higher rate of nephr
opathy and retinopathy, while there were no significant differences in
maternal age or parity compared to those without PIH/PE. Discriminant
analysis revealed that occurrence of nephropathy (p<0.001), retinopat
hy (p<0.01) and high HbA1c (p<0.01) in early pregnancy were independen
tly and significantly associated with occurrence of PIH/PE. Among the
463 patients without prepregnancy proteinuria 38 (8.2%) had PIH and 53
(11.5%) PE. The group with PE had, compared to the no PIH/PE group, s
ignificantly higher HbA1c (8.2% vs 7.4%, p<0.01). HbA1c was not signif
icantly different between the PIH and the no PIH/PE group (7.5% vs 7.4
%). Both the PIH and the PE group had significantly higher rate of ret
inopathy compared to the no PIH/PE group. If early HbA1c was equal to
or above control mean by +8 s.d., i.e. greater than or equal to 10.1%
the PI rate was 31.0% compared to 10.2% in those with HbA1c below that
value. Conclusions. We conclude that poor glycemic control in early p
regnancy is associated with increased risk of PE in non-proteinuric ty
pe 1 diabetic pregnancies.